This invention relates to ramp designs for loading and unloading a transducer to an operational relation to a recording surface of a rotatable disc.
Magnetic disc drives employ one or more discs, each having one or two recording surfaces. An actuator arm moves a transducer in an arcuate path between inner and outer tracks on each disc surface. When the disc drive is not in use, it is common to "park" the transducer at a predetermined position by operating the actuator arm to move the transducer to that position. In some designs, the "park" position of a transducer is at a selected region of a selected track on the disc surface where the transducer "lands" on the disc surface. When restarting the disc drive, aerodynamic characteristics of the head slider causes the slider to take off from the landed or park zone to a design flying height where the transducer is operational with the recording surface. Other types of disc drives employ a load/unload ramp design operable to engage the actuator arm carrying the transducer to restrain the transducer above the disc when the disc is stopped. While there are certain advantages to both types of parking techniques, the transducer ramp provides particular advantages during transportation of the disc drive by holding the transducer away from the disc surface so that sudden jolts or other shock to the disc drive do not cause the transducer to inadvertently "crash" into the disc surface, thereby causing damage to the disc and/or transducer.
Typically, the transducer ramp is located outside the outer peripheral edge of the discs and is moveable into the region of the discs to engage the transducer arm over an outer region of the discs. Also, typically, these devices include a snubber which restrains an edge of the disc from axially moving beyond a design limit. The snubbing device is typically a slotted mechanism which receives the outer edge of the disc and extends radially inward from the edge. The snubber includes surfaces spaced a small distance, such as about 1 mil, from the disc surface. During transit of the disc drive the snubbing device prevents the disc from axially moving beyond the design limit established by the snubber surfaces. However, if the surface of the slot engages the recording surface of the disc, damage may occur to the disc. There is a need, therefore, for an improved snubbing device for a load/unload ramp that will not injure the recording surface on the disc when the disc drive is subjected to shock.